Modelling the mechanical properties of cardiac muscle

• Published in: Progress in biophysics and molecular biology 1998-01, Vol.69 (2), p.289-331
• Main Authors: Hunter, P.J., McCulloch, A.D., ter Keurs, H.E.D.J.
• Format: Article
• Language: English
• Subjects: Actin Cytoskeleton - physiology; Animals; Biomechanical Phenomena; Calcium - metabolism; Elasticity; Ferrets; Heart - physiology; In Vitro Techniques; Kinetics; Mathematics; Models, Cardiovascular; Myocardial Contraction - physiology; Myocardium - metabolism; Rats; Space life sciences; Troponin C - metabolism
• ISSN: 0079-6107; 1873-1732
• DOI: 10.1016/S0079-6107(98)00013-3

A model of passive and active cardiac muscle mechanics is presented, suitable for use in continuum mechanics models of the whole heart. The model is based on an extensive review of experimental data from a variety of preparations (intact trabeculae, skinned fibres and myofibrils) and species (mainly rat and ferret) at temperatures from 20 to 27°C. Experimental tests include isometric tension development, isotonic loading, quick-release/restretch, length step and sinusoidal perturbations. We show that all of these experiments can be interpreted with a four state variable model which includes (i) the passive elasticity of myocardial tissue, (ii) the rapid binding of Ca 2+ to troponin C and its slower tension-dependent release, (iii) the kinetics of tropomyosin movement and availability of crossbridge binding sites and the length dependence of this process and (iv) the kinetics of crossbridge tension development under perturbations of myofilament length.